DAEWOO ELECTRONICS KOR-178HW, Service Manual

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TROUBLE SHOOTING GUIDE
Following the procedure below to check if the oven is defective or not.
1) Check grounding before trouble checking.
2) Be careful of the high voltage circuit.
3) Discharge the high voltage capacitor.
4) When checking the continuity of the switches, fuse or high voltage tranformer, disconnect one load wire from these
parts and check continuity with the AC plug removed. To do otherwise may result in a false reading or damage to
your meter.
(TROUBLE 1) Oven does not operate at all : any inputs can not be accepted.
NOTE : When electric parts are checked, be sure the power cord is not inserted the wall outlet.
Check wire harness, wiring and connection of the terminals and power cord before check the parts listed below.
CONDITION CHECK
Check continuity of interlock
monitor switch with door closed
Check continuity of of primary
interlock switch contact with door
partially open until interlock
monitor switch contact close
Malfunction of
interlock
monitor switch
Shorted
contacts of
primary
interlock switch.
RESULT
Continuity
No Continuity
No Continuity
Replace fuse
CAUSE REMEDY
Replace
(NOTE 1)
Fuse blows.
Replace
(NOTE 1)
Defective low
voltage
transformer
0
Ω
or infinite
Approx.
150~310
(normal)
Replace
Check continuity of primary
winding of low voltage
transformer
Defective high
voltage capacitor
Normal
Replace
Disconnect one side of the lead
wire connected form high
voltage transformer to the high
voltage capacitor and operate
the unit
Continuity
Defective high
voltage
transformer
Fuse again
blows
Replace